A control method for controlling an aircraft propulsion system comprising a gas turbine engine with a combustion chamber and an engine spool, the engine spool including a turbine downstream of the combustion chamber, a compressor upstream of the combustion chamber and a transmission shaft for driving the compressor via the turbine, and rotary machine coupled to the transmission shaft for generating electrical power by taking off mechanical power from the transmission shaft, the control method comprising the following successive steps:
- determining a current electrical power generated by the rotary machine,
- defining an idle speed which is a function of the current electrical power,
- establishing the engine speed above the idle speed,
- determining a current engine speed of the engine spool,
- defining a maximum authorized power which is a function of the current engine speed, and
- accelerating the engine spool, the current electrical power generated by the rotary machine being limited to the maximum authorized power.